A cephalosporin antibiotic; inhibits the growth of some clinical isolates of Corynebacterium, Streptococcus, and Staphylococcus (MIC90s = 0.03-8 μg/ml); inhibits the growth of some Citrobacter, Enterobacter, Klebsiella, Salmonella, Serratia, Shigella, and enteric bacilli species in addition to P. mirabilis and E. coli clinical isolates (MIC90s = ≤0.12-2 μg/ml); inhibits the growth of pneumococci strains (MICs = 0.5-2 mg/l) in vitro and in vivo in a mouse model of peritonitis (ED50s = 0.6-1.14 mg/kg)